This invention relates generally to integrated windshields and cab portions for aircraft, including high-speed aircraft, and associated methods.
Cab sections for current commercial airliners and business jets typically have a kink or bend in the contour of the fuselage just below the windshield. In some cases, the kink is provided to allow a more upright position for the windshield, which can reduce the accumulation of dust and other debris on the windshield, and/or windshield glare. This arrangement can also reduce the overall size of the windshield. FIGS. 1A and 1B illustrate an existing cab portion 10 having an existing windshield 13 and an existing contour 15 with a kink at the lower edge of the windshield 13. Pilots seated in the cab portion 10 have a reference eye position 17, and a field of vision 16 through the windshield 13.
One drawback with the arrangement shown in FIGS. 1A-1B is that the kink at the junction between the windshield 13 and the external surface of the cab portion 10 can increase the manufacturing complexity of the fuselage and can increase the loads transmitted to the aircraft airframe and/or windshield. Another drawback is that the kink can also increase the noise level in the cockpit by causing a disturbance in the airflow around the cab.
The present invention is directed toward cab portions with integrated windshields, and methods for forming such cab portions. A cab portion in accordance with one aspect of the invention includes an external flow surface having a generally rounded nose portion with a forward extremity, and a windshield aperture positioned only above and aft of the forward extremity of the rounded nose portion. The cab portion can further include a windshield disposed in the windshield aperture, wherein a contour of the external flow surface and the windshield extending from a position on the external flow surface beneath the windshield, aft over the windshield to a position on the external flow surface aft of and above the windshield, has a generally continuously smooth and unkinked shape. This arrangement can provide enhanced pilot visibility, reduced drag, increased aerodynamic performance, and reduced fuel consumption.
In a further aspect of the invention, the surface contour of the windshield can be generally conical. In yet a further aspect of the invention, the contour of the external flow surface and the windshield is a first contour intersecting a generally vertical plane passing through the external flow surface and the windshield at a center of the cab portion. A second contour of the external flow surface and the windshield intersecting a generally horizontal plane passing through the external flow surface and the windshield and extending aft over the windshield to a position on the external flow surface aft of the windshield can also have a generally continuously smooth and unkinked shape.
The invention is also directed toward methods for manufacturing an aircraft system. A method in accordance with one aspect of the invention includes fabricating an external flow surface having a generally rounded nose portion with a forward extremity and a windshield aperture positioned only above and aft of the forward extremity. The method can further include positioning a windshield in the windshield aperture, with a contour of the external flow surface and the windshield extending from a position on the external flow surface beneath the windshield, aft over the windshield to a position on the external flow surface aft of and above the windshield having a generally continuously smooth and unkinked shape.